Host processor systems may store and retrieve data using a storage device containing a plurality of host interface units (i.e. host adapters), disk drives, and other physical storage, and disk interface units (i.e., disk adapters). Such storage devices are provided, for example, by EMC Corporation of Hopkinton, Mass., and are disclosed in, for example, U.S. Pat. No. 5,206,939 to Yanai et a., U.S. Pat. No. 5,778,394 to Galtzur et al., U.S. Pat. No. 5,845,147 to Vishlitzky et al., and U.S. Pat. No. 5,857,208 to Ofek. The host systems access the storage device through a plurality of channels provided therewith. Host systems provide data and access control information through the channels of the storage device and the storage device provides data to the host systems also through the channels. The host systems do not address the physical storage of the storage device directly, but rather access what appears to the host systems as a plurality of logical volumes. The logical volumes may or may not correspond to the actual disk drives and/or other physical storage.